1. Field of the Invention
This invention relates to apparatuses for winding magnetic tape into cassette cases with guard panels, and especially relates to apparatuses which extract leader tape from a cassette case, connect magnetic tape between the leader tape, and wind the tape onto a hub inside the cassette case.
2. Description of the Related Art
There are two basic production methods for magnetic recording tape cassettes. The first method involves loading cassette cases with reel hubs which have already been wound with magnetic tape outside the case. This method requires a large complex apparatus, but the magnetic tape winding time is short, and the processing rate is high. This method is suitable for large scale production facilities.
In the second method, cassettes are prepared by loading reel hubs joined by a length of leader tape into cassette cases. Leader tape is extracted from each cassette case, magnetic tape is connected to the leader tape, and a hub is rotated to wind magnetic tape into the cassette case. This method is characterized in that cassettes can be wound with magnetic tape using a simple small scale winding apparatus. Japanese Patent Publication No. 45203/1977 discloses an apparatus which employs the second method. In this apparatus, as shown in FIG. 9, leader tape 92 is extracted from the cassette case 91, and attached to the first 93 and second 94 tape retainers. The leader tape 92 is cut between the first 93 and second 94 tape retainers to which it is attached, and the third tape retainer 95, which moves as a unit with the second tape retainer 94, and holds magnetic tape 96, is moved next to the first tape retainer 93. Magnetic tape 96 is connected to the end of the leader tape 92, the tape is released from the first 93 and third 95 tape retainers, and the hub inside the cassette case is rotated to wind up the tape. After a predetermined length of magnetic tape 96 has been wound, it is again attached to, and cut between, the first 93 and third 95 tape retainers. The second 94 and third 95 tape retainers are then moved, such that the second tape retainer 94 assumes a position next to the first tape retainer 93, the end of the magnetic tape 96 is joined to the previously cut end of the leader tape 92, and the remaining extracted tape is wound into the cassette case.
In addition to this, an apparatus with a different system of supplying magnetic tape to the severed leader tape has also been developed (Japanese Patent Publication No. 30444/1974). In this apparatus as well, leader tape is extracted from the cassette case, the leader tape is cut, and magnetic tape is joined to one end. After magnetic tape is wound into the cassette case, it is cut, and the cut end of leader tape from the opposite reel is joined with the cut end of the wound magnetic tape.
The inventor has further developed the apparatus for winding magnetic tape shown in FIG. 1, which is disclosed in copending application, Ser. No. 911,985. In this apparatus, leader tape 2 is attached to the first 11 and second 12 tape retainers. Once severed, the cut end of leader tape attached to the second tape retainer 12 is moved to a standby position. At this point, magnetic tape 6 held by the third tape retainer 13 is moved next to the first tape retainer 11, and joined with the leader tape 2. Magnetic tape 6 is then wound onto the hub 24.
In these former models leader tape is severed between reels, and one cut end is moved to a standby position. This movement gives rise to leader tape slack which has a tendency to separate from the extraction guide and, for example, get in the path of the magnetic tape during winding. For this reason, the occurrence of leader tape slack in the former apparatus has been a distinct drawback.
Ideally, to minimize dust contamination, leader tape slack should be withdrawn within the cassette case. In order to wind in the slack leader tape, the hub connected to that piece of leader tape can be rotated. However, the hub with the slack leader tape is not the hub on which magnetic tape is wound, and hence, there is no winding means for that hub. Consequently, by this method, a complicated mechanism is required to take in leader tape slack by applying a fixed torque to the hub with no winding means.